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Date:   Fri, 2 Oct 2020 16:07:52 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Grygorii Strashko <grygorii.strashko@ti.com>
Cc:     "David S. Miller" <davem@davemloft.net>, <netdev@vger.kernel.org>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Sekhar Nori <nsekhar@ti.com>, <linux-kernel@vger.kernel.org>,
        <linux-omap@vger.kernel.org>,
        Murali Karicheri <m-karicheri2@ti.com>
Subject: Re: [PATCH net-next 0/8] net: ethernet: ti: am65-cpsw: add multi
 port support in mac-only mode
Message-ID: <20201002160752.1166cffe@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
In-Reply-To: <20201002160421.59363229@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
References: <20201001105258.2139-1-grygorii.strashko@ti.com>
        <20201001160847.3b5d91f1@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
        <c758885c-6834-e689-2356-81291e4628e8@ti.com>
        <20201002160421.59363229@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
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On Fri, 2 Oct 2020 16:04:21 -0700 Jakub Kicinski wrote:
> On Fri, 2 Oct 2020 12:56:43 +0300 Grygorii Strashko wrote:
> > On 02/10/2020 02:08, Jakub Kicinski wrote:  
> > > On Thu, 1 Oct 2020 13:52:50 +0300 Grygorii Strashko wrote:    
> > >> This series adds multi-port support in mac-only mode (multi MAC mode) to TI
> > >> AM65x CPSW driver in preparation for enabling support for multi-port devices,
> > >> like Main CPSW0 on K3 J721E SoC or future CPSW3g on K3 AM64x SoC.
> > >>
> > >> The multi MAC mode is implemented by configuring every enabled port in "mac-only"
> > >> mode (all ingress packets are sent only to the Host port and egress packets
> > >> directed to target Ext. Port) and creating separate net_device for
> > >> every enabled Ext. port.    
> > > 
> > > Do I get it right that you select the mode based on platform? Can the
> > > other mode still be supported on these platforms?
> > > 
> > > Is this a transition to normal DSA mode where ports always have netdevs?  
> >
> > The idea here is to start in multi mac mode by default, as we still
> > have pretty high demand for this. Then, and we are working on it, the
> > switchdev mode is going to be introduces (not DSA). The switch
> > between modes will happen by using devlink option - the approach is
> > similar to what was used for Sitara CPSW cpsw_new.c driver [1].  
> 
> What's unclear from the patches is whether the default configuration
> for already supported platforms will change?
> 
> All the patches sound like they are "in preparation for support of K3
> J721E" etc. So this is just code restructuring with no user-visible
> changes?

Another way of putting the question perhaps would be - is num_ports
always 1 for existing platforms?